Computer-aided prosthesis alignment

Abstract

Systems and methods for computer-aided alignment and positioning of a prosthesis component onto a target host bone, such as in joint resurfacing arthroplasty, are discussed. A system for can include a processor unit and a user interface unit. The processor unit can receive a target bone model including a first data set representing a target bone surface, and a prosthesis model including a second data set representing a prosthesis surface. The prosthesis, when positioned against the target bone, is configured to at least partially replace the articulation surface. The processor unit can generate an articulation interface representation that indicates spatial misalignment between one or more portions of the prosthesis surface and one or more portions of the target bone surface when the prosthesis model is positioned against the target bone model.

1 - 32 . (canceled) 
     
     
         33 . A prosthesis-alignment computing device, comprising:
 a processor unit, configured to:
 calculate one or more regional misalignments between a target bone model including a representation of a first surface of the target bone including an articulation surface of the target bone and a prosthesis model including a representation of a second surface of the prosthesis configured to at least partially replace the articulation surface, wherein calculating the one or more regional misalignments comprises:
 determining corresponding segments in the target bone model and the prosthesis model; 
 extracting one or more features from the corresponding segments; and 
 calculating a similarity measure between the corresponding segments based on the extracted one or more features of the corresponding segments; and 
 
 generate a visual articulation interface representation based on the one or more regional misalignments, the articulation interface representation indicative of one or more portions of the surface of the prosthesis being spatially misaligned with a respective one or more portions of the articulation surface when the prosthesis model is positioned against the target bone model. 
   
     
     
         34 . The device of  claim 33 , wherein the corresponding segments in the target bone model and the prosthesis model are determined based on a location or morphological features of surface representations of the target bone model and the prosthesis model. 
     
     
         35 . The device of  claim 33 , wherein the extracted one or more features are intensity based features. 
     
     
         36 . The device of  claim 35 , wherein the similarity measure is computed as a correlation coefficient, mutual information, or ratio image uniformity based on the extracted one or more intensity features of the corresponding segments. 
     
     
         37 . The device of  claim 33 , wherein the similarity measure comprises distance measurements between the extracted one or more features in the corresponding segments. 
     
     
         38 . The device of  claim 33 , wherein the target bone model includes a first three-dimensional graphical representation of the first surface of the target bone, and the prosthesis model includes a second three-dimensional graphical representation of the second surface of the prosthesis. 
     
     
         39 . The device of  claim 33 , wherein the processor unit is further configured to generate a plurality of specified angles of views of at least one of the target bone model, the prosthesis model, and the articulation interface representation. 
     
     
         40 . The device of  claim 33 , wherein the processor unit being configured to generate the visual articulation interface representation comprises the processor unit being configured to generate a color-coded representation, the color-coded representation including a first color associated with a first portion of the second surface of the prosthesis being misaligned in a first direction with a first portion of the first surface of the target bone, and a different second color associated with a second portion of the second surface of the prosthesis being misaligned in a second direction with a second portion of the first surface of the target bone. 
     
     
         41 . The device of  claim 38 , wherein the color-coded representation further includes a third color different from the first and second colors, the third color associated with a third portion of the second surface of the prosthesis being disposed within a third specified range relative to, and not misaligned with, a third portion of the first surface. 
     
     
         42 . The device of  claim 33 , wherein the processor unit being configured to generate the visual articulation interface representation comprises the processor unit being configured to generate a color-coded representation, the color-coded representation including a first set of colors each associated with the first portion of the second surface of the prosthesis being misaligned in the first direction with the first portion of the first surface of the target bone by a first specified amount, and a second set of colors each associated with the second portion of the second surface of the prosthesis being misaligned in the second direction with the second portion of the first surface of the target bone by a second specified amount. 
     
     
         43 . The device of claim  1 , wherein the processor unit is further configured to generate an annotative representation, the annotative representation including a first marking associated with a first portion of the second surface of the prosthesis being misaligned in a first direction with a first portion of the first surface of the target bone, and a different second marking associated with a second portion of the second surface of the prosthesis being misaligned in a second direction with a second portion of the first surface of the target bone. 
     
     
         44 . The device of  claim 33 , wherein the processor unit is further configured to update the visual articulation interface representation in response to user input including the indication of the change in position of one or both of the target bone and prosthesis models. 
     
     
         45 . The device of  claim 33 , wherein the processor unit is further configured to compute an alignment index using the visual articulation interface representation, and to determine a desirable alignment between the first surface of the target bone and the second surface of the prosthesis in response to the alignment index meeting a specified criterion. 
     
     
         46 . A method of aligning a prosthesis surface to a target bone surface, the method comprising:
 calculating one or more regional misalignments between a target bone model including a representation of a first surface of the target bone including an articulation surface of the target bone and a prosthesis model including a representation of a second surface of the prosthesis configured to at least partially replace the articulation surface, wherein calculating the one or more regional misalignments comprises:
 determining corresponding segments in the target bone model and the prosthesis model; 
 extracting one or more features from the corresponding segments; and 
 calculating a similarity measure between the corresponding segments based on the extracted one or more features of the corresponding segments; and 
   generating a visual articulation interface representation based on the one or more regional misalignments, the articulation interface representation indicative of one or more portions of the surface of the prosthesis being spatially misaligned with a respective one or more portions of the articulation surface when the prosthesis model is positioned against the target bone model.   
     
     
         47 . The method of  claim 46 , wherein the corresponding segments in the target bone model and the prosthesis model are determined based on a location or morphological features of surface representations of the target bone model and the prosthesis model. 
     
     
         48 . The method of  claim 46 , wherein the extracted one or more features are intensity based features. 
     
     
         49 . The method of  claim 48 , wherein the similarity measure is computed as a correlation coefficient, mutual information, or ratio image uniformity based on the extracted one or more intensity features of the corresponding segments. 
     
     
         50 . The method of  claim 46 , wherein the similarity measure comprises distance measurements between the extracted one or more features in the corresponding segments. 
     
     
         51 . The method of  claim 46 , wherein the target bone model includes a first three-dimensional graphical representation of the first surface of the target bone, and the prosthesis model includes a second three-dimensional graphical representation of the second surface of the prosthesis. 
     
     
         52 . The method of  claim 46 , further comprising generating a plurality of specified angles of views of at least one of the target bone model, the prosthesis model, and the articulation interface representation. 
     
     
         53 . The method of  claim 46 , wherein generating the visual articulation interface representation comprises generating a color-coded representation, the color-coded representation including a first color associated with a first portion of the second surface of the prosthesis being misaligned in a first direction with a first portion of the first surface of the target bone, and a different second color associated with a second portion of the second surface of the prosthesis being misaligned in a second direction with a second portion of the first surface of the target bone. 
     
     
         54 . The method of  claim 53 , wherein the color-coded representation further includes a third color different from the first and second colors, the third color associated with a third portion of the second surface of the prosthesis being disposed within a third specified range relative to, and not misaligned with, a third portion of the first surface. 
     
     
         55 . The method of  claim 46 , wherein generating the visual articulation interface representation comprises generating a color-coded representation, the color-coded representation including a first set of colors each associated with the first portion of the second surface of the prosthesis being misaligned in the first direction with the first portion of the first surface of the target bone by a first specified amount, and a second set of colors each associated with the second portion of the second surface of the prosthesis being misaligned in the second direction with the second portion of the first surface of the target bone by a second specified amount. 
     
     
         56 . The method of  claim 46 , further comprising generating an annotative representation, the annotative representation including a first marking associated with a first portion of the second surface of the prosthesis being misaligned in a first direction with a first portion of the first surface of the target bone, and a different second marking associated with a second portion of the second surface of the prosthesis being misaligned in a second direction with a second portion of the first surface of the target bone. 
     
     
         57 . The method of  claim 46 , further comprising updating the visual articulation interface representation in response to user input including the indication of the change in position of one or both of the target bone and prosthesis models. 
     
     
         58 . The method of  claim 46 , further comprising computing an alignment index using the visual articulation interface representation, and to determine a desirable alignment between the first surface of the target bone and the second surface of the prosthesis in response to the alignment index meeting a specified criterion. 
     
     
         59 . A non-transitory machine-readable storage medium including instructions that, when executed by a machine, cause the machine to:
 calculate one or more regional misalignments between a target bone model including a representation of a first surface of the target bone including an articulation surface of the target bone and a prosthesis model including a representation of a second surface of the prosthesis configured to at least partially replace the articulation surface, wherein calculating the one or more regional misalignments comprises:
 determining corresponding segments in the target bone model and the prosthesis model; 
 extracting one or more features from the corresponding segments; and 
 calculating a similarity measure between the corresponding segments based on the extracted one or more features of the corresponding segments; and 
   generate a visual articulation interface representation based on the one or more regional misalignments, the articulation interface representation indicative of one or more portions of the surface of the prosthesis being spatially misaligned with a respective one or more portions of the articulation surface when the prosthesis model is positioned against the target bone model.   
     
     
         60 . The medium of  claim 59 , wherein the corresponding segments in the target bone model and the prosthesis model are determined based on location or morphological features of surface representations of the target bone model and the prosthesis model. 
     
     
         61 . The medium of  claim 59 , wherein the extracted one or more features are intensity based features. 
     
     
         62 . The medium of  claim 61 , wherein the similarity measure is computed as a correlation coefficient, mutual information, or ratio image uniformity based on the extracted one or more intensity features of the corresponding segments. 
     
     
         63 . The medium of  claim 59 , wherein the similarity measure comprises distance measurements between the extracted one or more features in the corresponding segments. 
     
     
         64 . The medium of  claim 59 , wherein the target bone model includes a first three-dimensional graphical representation of the first surface of the target bone, and the prosthesis model includes a second three-dimensional graphical representation of the second surface of the prosthesis. 
     
     
         65 . The medium of  claim 59 , further comprising instructions that cause the machine to:
 generate a plurality of specified angles of views of at least one of the target bone model, the prosthesis model, and the articulation interface representation.   
     
     
         66 . The medium of  claim 59 , wherein the instructions that cause the machine to generate the visual articulation interface representation comprise instructions that cause the machine to generate a color-coded representation, the color-coded representation including a first color associated with a first portion of the second surface of the prosthesis being misaligned in a first direction with a first portion of the first surface of the target bone, and a different second color associated with a second portion of the second surface of the prosthesis being misaligned in a second direction with a second portion of the first surface of the target bone. 
     
     
         67 . The medium of  claim 66 , wherein the color-coded representation further includes a third color different from the first and second colors, the third color associated with a third portion of the second surface of the prosthesis being disposed within a third specified range relative to, and not misaligned with, a third portion of the first surface. 
     
     
         68 . The medium of  claim 59 , wherein the instructions that cause the machine to generate the visual articulation interface representation comprise instructions that cause the machine to generate a color-coded representation, the color-coded representation including a first set of colors each associated with the first portion of the second surface of the prosthesis being misaligned in the first direction with the first portion of the first surface of the target bone by a first specified amount, and a second set of colors each associated with the second portion of the second surface of the prosthesis being misaligned in the second direction with the second portion of the first surface of the target bone by a second specified amount. 
     
     
         69 . The medium of  claim 59 , further comprising instructions that cause the machine to:
 generate an annotative representation, the annotative representation including a first marking associated with a first portion of the second surface of the prosthesis being misaligned in a first direction with a first portion of the first surface of the target bone, and a different second marking associated with a second portion of the second surface of the prosthesis being misaligned in a second direction with a second portion of the first surface of the target bone.   
     
     
         70 . The medium of  claim 59  further comprising instructions that cause the machine to:
 update the visual articulation interface representation in response to user input including the indication of the change in position of one or both of the target bone and prosthesis models. 
 
     
     
         71 . The medium of  claim 59  further comprising instructions that cause the machine to:
 compute an alignment index using the visual articulation interface representation, and to determine a desirable alignment between the first surface of the target bone and the second surface of the prosthesis in response to the alignment index meeting a specified criterion. 
 
     
     
         72 . A prosthesis-alignment computing device, comprising:
 a processor unit, configured to:
 calculate one or more regional misalignments between a target bone model including a representation of a first surface of the target bone including an articulation surface of the target bone and a prosthesis model including a representation of a second surface of the prosthesis configured to at least partially replace the articulation surface, wherein calculating the one or more regional misalignments comprises:
 determining corresponding segments in the target bone model and the prosthesis model based on a location or morphological features of surface representations of the target bone model and the prosthesis model; 
 extracting one or more features from the corresponding segments; and 
 calculating a similarity measure between the corresponding segments based on the extracted one or more features of the corresponding segments; and 
 
 generate a visual articulation interface representation based on the one or more regional misalignments, the articulation interface representation indicative of one or more portions of the surface of the prosthesis being spatially misaligned with a respective one or more portions of the articulation surface when the prosthesis model is positioned against the target bone model. 
   
     
     
         73 . A prosthesis-alignment computing device, comprising:
 a processor unit, configured to:
 calculate one or more regional misalignments between a target bone model including a representation of a first surface of the target bone including an articulation surface of the target bone and a prosthesis model including a representation of a second surface of the prosthesis configured to at least partially replace the articulation surface, wherein calculating the one or more regional misalignments comprises:
 determining corresponding segments in the target bone model and the prosthesis model; 
 extracting one or more features from the corresponding segments; and 
 calculating a similarity measure between the corresponding segments based on the extracted one or more features of the corresponding segments, wherein the similarity measure comprises distance measurements between the extracted on or more features in the corresponding segments; and 
 
 generate a visual articulation interface representation based on the one or more regional misalignments, the articulation interface representation indicative of one or more portions of the surface of the prosthesis being spatially misaligned with a respective one or more portions of the articulation surface when the prosthesis model is positioned against the target bone model.